The natural history of plants, their forms, growth, reproduction, and distribution; . or many-rayed stars, each supported on a short stalk (see figs. 78^ and 77^).The rays of the stellate cells are frequently forked, as in Draha Thomasii (seefigs. 77^). In rare cases they have a comparatively large central portion, and areonly divided at their circumference into short rays; they then look exactly likesmall sunshades spread out over the leaf-surface. This elegant form, which isrepresented in figs. 77^ and 77 ^ has a particularly beautiful appearance in PROTECTIVE ARRANGEMENTS ON THE EPIDERMIS.
The natural history of plants, their forms, growth, reproduction, and distribution; . or many-rayed stars, each supported on a short stalk (see figs. 78^ and 77^).The rays of the stellate cells are frequently forked, as in Draha Thomasii (seefigs. 77^). In rare cases they have a comparatively large central portion, and areonly divided at their circumference into short rays; they then look exactly likesmall sunshades spread out over the leaf-surface. This elegant form, which isrepresented in figs. 77^ and 77 ^ has a particularly beautiful appearance in PROTECTIVE ARRANGEMENTS ON THE EPIDERMIS. 323 Koniga spinosa, a member of the Mediterranean flora. All these clothing haiiS,with star-shaped indented upper cells, are grouped together under the name ofstellate hairs (pili stellati). In Cruciferae and MalvaceoB they occur in endlessvariety. When the uppermost cell of the group forming the stellate hair is divided byseparation walls, which in part are placed perpendicularly to the leaf-surf ace,branched hairs are the result. In branched hairs the branches, which are almost. Fig. 79.—Flinty armour of Rochea falcata. I Section perpendicular to the leaf-surface. 2 Surface view; on the right hand the vesicular distended portion of a fewsuperficial cells is removed and the stomata are brought into view; x350. always arranged in a stellate manner and are usually unicellular, can be dis-tinguished from the part which supports the branches. This portion usually lookslike a pedestal, and is sometimes multicellular, sometimes formed from a single the pedestal is very short, and the cell supported by it is divided by severalradiating divergent septa, which are either oblique or perpendicular to the leaf-surface, tufted hairs (pili fasciculati) are formed. These look like sea-urchinslying on the surface in close proximity to each other; they vary very much in thesize, number, length, and direction of their branches, and they are particularlyabundant on the cinquefoils (P
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1902
